The present invention relates to a stretcher which can be also used as a wheelchair. More particularly, the present invention relates to a frame coupling structure in a stretcher which can change its configuration to a wheelchair, a mechanism for supporting a head or a back of a patient, a lever device which is gripped when pushing by hand for movement, a support structure of a safety bar, and others.
There is a stretcher having a back portion which can be raised in accordance with a posture of a stretcher user such as a person in need of nursing case or a patient who finds it difficult to sit up or move by him/herself (they are generically referred to as a xe2x80x9cpatientxe2x80x9d in this specification), or a stretcher which can be transformed into a wheelchair by raising a back portion and bending a leg portion downwards (Japanese patent application laid-open No. 52459-1998). Such a stretcher can be transformed into a wheelchair after transferring a patient who is in a recumbent position from a bed to the stretcher so that the patient can be moved in a sitting posture.
This type of stretcher, however, has various problems such as described below.
As a first problem, there is one concerning a frame coupling structure. That is, a frame of a conventional stretcher is assembled so as to be capable of being bent at parts corresponding to a lumbar or knees by coupling a plurality of pipes by pin and others so that they can swivel without restraint. For example, a right pipe on an upper body side and a right pipe on a lower body side are coupled with a left pipe on the upper body side and a left pipe on the lower body side respectively by different pins so as to be capable of swiveling without restraint. When the frame is constituted by separately coupling the right and left pipes with each other so as to be capable of swiveling in this manner, the torsion is generated in the frame, leading to the insufficient rigidity. Further, since a hole is directly formed to the pipe to insert a pin therethrough, the hole tends to be enlarged due to long-term use so that a bent portion may rattle, which is inferior in the durability.
Moreover, an armrest for preventing a patient from falling off and facilitating a comfortable posture for the patient is needed when the stretcher is transformed into a wheelchair. This requires a troublesome operation such as going to the trouble to attach after transformation into the wheelchair the armrest as an additional member which has been detached in the stretcher configuration or lifting up and fixing the armrest which has been kept down in the stretcher mode, thus resulting in the bad usability. In addition, when transferring a patient from the stretcher to a bed or from the bed to the stretcher, the strength which can withstand a weight of the patient is needed since the weight is also applied to the armrest portion. However, the conventional frame structure is a one-column support structure or a cantilever support structure, and hence stagger may be caused or the sufficient strength may not be obtained.
A second problem relates to stability of a patient during use in the wheelchair configuration. That is, since the patient may not be able to maintain the posture by him/herself, it is necessary to secure stability by firmly supporting the patient""s body or head in order to prevent the off balance or tumble of the patient when using the stretcher in the wheelchair configuration. However, in the conventional structure, since the inclination of a seat or a backrest is fixed when transformed into the wheelchair or no mechanism for supporting the body is provided, the patient may tumble down when he/she bends forward if a preferred position as a wheelchair is taken.
A third problem lies in that support of a head of a patient is not taken into consideration in particular in the conventional stretcher. For example, a patient is obliged to keep his/her head low in a flat stretcher consisting of one solid timber mat. This posture increases a blood flow to the head or brings a patient a sense of insecurity that he/she may slide off to the head portion side. Such a trouble may give a sense of discomfort or insecurity to a patient even if the time required for movement is short. Additionally, although a pillow is put on the stretcher in order to appropriately hold the head portion in some cases, the pillow may move to cause the head to slide off or the pillow may be lost, which is inconvenient. If the pillow is fixed to the mat, however, the pillow can be an obstacle for transferring a patient from the bed, which is not preferable. On the other hand, a stretcher having a head support portion provided thereto has been developed, but the head support portion is only partitioned from a portion supporting a part from neck down for the convenience sake, and a patient must take a uniform posture irrespective of his/her physical constitution or symptom. Such a problem is also common to the stretcher which can be transformed into a wheelchair as well as a general stretcher. When it is used as a stretcher, a mat forming a single plane must support the head of a patient. Further, when it is used as a wheelchair, it is hard for the patient to lean his/her head to take a comfortable posture.
A fourth problem relates to movement of a stretcher or transfer of a patent on the stretcher. That is, in a nursing-care system for transferring a patient from a bed to a stretcher or from the stretcher to the bed in a recumbent position, it is considered that, for example, a tool called a transfer bar is used to facilitate transfer of the patient (international patent publication No. WO99/30662).
When transferring a patient from a bed and the like to a stretcher by utilizing this transfer bar, a bracket must be set on the opposite side which is not in contact with the bed of the stretcher so that the transfer bar is rotatably supported. Here, since the bracket for supporting the transfer bar protrudes above the stretcher, it may be an obstacle for allowance or medical attention to a patient or may give annoyance when the bracket is attached. It is desired that the bracket can be detachable with respect to the stretcher.
If the bracket is detached each time, however, attachment and detachment take time, and a place for accommodating the removed bracket is also required. Further, the bracket removed from the stretcher may be lost in some cases. Additionally, when pushing and moving the stretcher, since the stretcher has such a structure as that a frame which is as tall as or lower than a mat surface must be grabbed, a nursing personnel or a caregiver must stoop to push and pull the stretcher, thereby resulting in a burden on the lumbar and the like.
A fifth problem concerns a safety bar provided in order to prevent a patient from falling off. That is, the safety bar must be detachable for transfer, but detaching the safety bar each time for transfer is troublesome and inconvenient. Moreover, storage of the removed safety bar is troublesome and it may be lost. Although a structure such that the safety bar is moved up and down to be retracted can be considered, no fluctuation is made at positions of the safety bar and its support structure in their widthwise directions in this case. Therefore, the safety bar protruding in the side direction from the mat becomes an obstacle to form a gap between the safety bar and the bed and the like when the stretcher is pulled alongside the bed and the like.
It is, therefore, an object of the present invention to provide a stretcher which has the high frame rigidity and which is superior in the durability. It is another object of the present invention to provide a stretcher which can be transformed into a wheelchair from the stretcher and vice versa by one operation and which can expand a mat surface area in the stretcher configuration. It is still another object of the present invention to provide a stretcher which is superior in stably maintaining the posture of a patient when used as a wheelchair. It is yet another object of the present invention to provide a stretcher which can maintain a head of a patient in an appropriate posture. It is a further object of the present invention to provide a stretcher by which a nursing personnel or a caregiver can take a comfortable posture when he/she pushes and moves the stretcher. It is a still further object of the present invention to provide a stretcher having a bracket supporting a transfer bar. It is a yet another object of the present invention to provide a stretcher by which a safety bar can be set to the side of a mat according to need and retracted to a position which can not be an obstacle for transfer of a patient.
To achieve this aim, the present invention provides a stretcher comprising a cart and a frame which is mounted thereon and supports a mat for putting a patient thereon, wherein the frame is divided into at least four portions, i.e., an above knee portion constituting a seat for supporting a femoral region of a patient, a lumbar portion constituting a backrest for supporting an upper part of a patient""s body, an armrest portion constituting an armrest and a below knee portion capable of supporting a lower limb region; the above knee portion, the lumbar portion, the armrest portion and the below knee portion are rotatably coupled with each other; changing the positional relationship of these portions enables transformation into a stretcher configuration in which a flat mat surface are including the armrest portion and the below knee portion is formed and a wheelchair configuration in which the mat is bent and the armrest is raised; and a patient can be mounted to be moved in both the stretcher configuration and the wheelchair configuration. Therefore, it is possible to perform transformation into the stretcher configuration in which an operation for rotating the divided frames rotatably coupled with each other changes an angle of the armrest portion and the above knee portion relative to the lumbar portion, an angle of the above knee portion and the below knee portion and an angle of the below knee portion and the armrest portion, respectively, so that these portions can be arranged on a straight line to form a flat mat surface and into the wheelchair configuration in which the frames are bent and separated from each other to form the seat, the backrest, the armrest and others. In addition, the armrest and a part of supporting calf parts of legs can be used in the wheelchair configuration and they are also used in the stretcher portion, resulting in expanding the mat surface area and improving the usability as a stretcher.
Here, the frame couples a middle part of the lumbar portion and a middle part of the below knee portion with the cart so as to be capable of oscillating without restraint. As seen in a side view, there is constituted a four-node rotation linkage of a parallelogram with a coupled portion between the lumbar portion and the armrest portion, a coupled portion between the armrest portion and the below knee portion, a coupled portion between the below knee portion and the cart, and a coupled portion between the cart and the lumbar portion as four peaks. It is preferable that rotating the lumbar portion around the coupled portion relative to the cart so as to be reclined rearwards crushes the parallelogram so that the four respective portions are arranged on the same plane and, on the other hand, rotating the lumbar portion so as to be drawn up restores the parallelogram so that the armrest portion is upheaved. In this case, when the lumbar portion is tried to be reclined to enter the stretcher mode, the armrest portion is pulled down and the above knee portion is upheaved. At the same time, when the below knee portion is reclined rearwards, the above knee portion, the below knee portion and the lumbar portion constituting the backrest, including the armrest portion, are straightly arranged on a line connecting the two coupled portions relative to the cart and the frame, thereby forming a flat mat surface area. Meanwhile, when entering the wheelchair mode, by only pulling up the lumbar portion, the parallelogram is restored, and the lumbar portion is upheaved substantially horizontally. Therefore, pulling up or attaching the armrest portion does not have to be carried out, in addition to the operation for raising the lumbar portion, and it is possible to transform into the wheelchair.
Further, in the stretcher according to the present invention, the right and left coupled portions of the frames are constituted by one core material piercing one coupled portion and the other coupled portion associated with the former portion and a sleeve which is rotatably fitted into the core material and has the frame fixed thereto. Rotating the sleeve around the core material causes the frame to be bent. Thus, by rotating the sleeve to which the right and left frames are fixed around the core material, the lumbar portion, the above knee portion, the below knee portion and the armrest portion can be bent at the respective coupled portions so that each portion can be pulled up or reclined. Thus, the frames can smoothly transform without involving distortion between the right and left frames. Additionally, since the sleeve comes into contact with the core material on a large surface area, the sleeve is free from a problem of deformation or an enlarged diameter caused due to long-term use, which is superior in the durability without unsteadiness in the coupled portions. That is, the rigidity and the durability of the frame can be improved while assuring the smooth bending operation at each coupled portion.
As to the coupled portions of the frames, it is determined that a value of a total length of all the sleeves fitted in the core material is substantially equal to a value of an entire length of the core material, and it is preferable that a flange member for preventing the sleeve from coming off is attached to the end surface of the core material. In this case, when assembling the frame, by only fitting the sleeve to the core material and then attaching the flange portions to both ends of the core member, a plurality of frame materials can be rotatably coupled with each other without the sleeve coming off. Therefore, the productivity can be improved and the cost can be suppressed. Moreover, the sleeve can be supported by the flange member so that it does not come off the core material. The sleeve can be positioned in the axial direction by only attaching the flange member, thus avoiding unsteadiness in the sleeve.
Further, it is preferable that the frame of the stretcher according to the present invention is provided with a lock mechanism with the four-node rotation linkage of the parallelogram as a fixed link. In this case, changeover to the stretcher configuration or the wheelchair configuration can be enabled by upheaving or reclining the lumbar portion by utilizing deformation of the four-node rotation linkage in the unlocked state of the lock mechanism. When the lock mechanism is locked, the link is fixed in the form at that moment, which avoids deformation of the frame. In other words, the frame can be fixed with an arbitrary shape/angle by using the lock mechanism.
Here, it is preferable that a plurality of the lock mechanisms are provided and they are attached at installation angles different from each other. Although the rigidity of the lock mechanism for fixing the angle of the frame tends to be weak when the lock mechanism is fully extended, providing the plurality of the lock mechanisms at different attachment angles can prevent all the lock mechanisms from being fully extended at the same time. Further, the sufficient rigidity for constantly locking the frame can be assured irrespective of the angle of the frame.
In addition, the stretcher according to the present invention includes an angle adjustment mechanism which can incline the entire frame with respect to the cart between the frame and the cart. In this case, by changing an inclination angle of the entire frame with respect to the cart by using the angle adjustment mechanism, the entire frame can be inclined, and the seat, the backrest and the like can be reclined without changing an angle between the seat and the backrest and the like in the wheelchair configuration. Therefore, the posture of a patient can be stably maintained while preventing the patient from tumbling forward or collapsing his/her posture. Furthermore, by returning the angle of the frame to the horizontal state, or by inclining it to the front lower side, a patient""s action to get on and off can be facilitated.
Here, the angle adjustment mechanism preferably includes: a support member which is provided between the frame and the cart to support the frame and coupled with the cart so as to be capable of oscillating without restraint; and a tilt angle variable mechanism which can fix the support member capable of oscillating to the cart at an arbitrary position. In this case, by releasing restriction of the support member by the tilt angle variable mechanism, the support member can be swiveled around the support axis between the support member and the cart in an arbitrary direction so that the entire frame can be tilted. Thus, by fixing the support member by the tilt angle variable mechanism at a maximum tilt position or an arbitrary tilt position up to the maximum tilt position, e.g., a slightly retroverted position, that tilting can maintain the tilt angle of the entire frame constant.
In addition, it is preferable that the angle adjustment mechanism is a gas spring with a lock mechanism. In this case, when unlocking the support member by releasing the lock mechanism of the tilt angle variable mechanism, since the force for pushing back the support member to its original position is imparted by an accumulated gas pressure of a gas spring at the time of backward tilting of the frame, it is possible to return the entire frame to its original position even if a patient is in a sitting position. Locking of the tilt angle variable mechanism can maintain that tilt.
Further, in the stretcher according to the present invention, it is preferable that a portion for supporting the frame of the cart and the lock mechanism are arranged against both the right and left sides of the cart and a bag accommodating space is formed between the frame and the cart. In this case, a tray or a basket can be set in the bag accommodating space so that nursing care goods can be mounted to be carried.
Moreover, in the stretcher according to the present invention, a headrest is provided at a portion of the frame for supporting a head of a patient. With this structure, the patient""s head can be maintained in an appropriate posture at a preferable height in the stretcher. Therefore, the patient can take a comfortable posture such that his/her head can be held in a state which does not burden his/her body in either a recumbent posture or a sitting posture.
Here, the headrest required for the stretcher becomes flat when transferring a patient so as not to be an obstacle for transfer. On the other hand, when a patient lies face up on the stretcher or sits on the stretcher in the wheelchair mode, it is preferable that the height or the angle of the headrest can be finely adjusted in accordance with a posture, a symptom or a physical construction of each patient. Therefore, the present inventor considered that the height and the angle of the headrest can be easily and rapidly adjusted and a head of each patient having a different physical construction or symptom can be supported at a preferable position. In order to meet such a demand, the headrest of the stretcher according to the present invention is adjustably attached to the frame by a first bracket fixed to the frame, a second bracket fixed to the headrest in such a manner that at least a part of it overlaps on the first bracket, and coupling means which pierces the first and second brackets and allows or prohibits relative rotation of both brackets; a through hole of any one bracket which the coupling means pierces is determined as a long hole elongated in a direction vertical to the frame so that the headrest can move close to or away from the frame within a stroke range of the long hole; a shoulder portion is formed to one of the first or second bracket; and a restriction pin which comes into contact with the shoulder portion only when the headrest moves close to the frame to avoid relative rotation between the first and second brackets is provided to the other.
Therefore, the headrest is retracted to a position which is flush with or parallel with the mat surface (this position will be referred to as a xe2x80x9cheadrest retracted positionxe2x80x9d hereunder) to be fixed when a patient transfers and, on the other hand, the coupling means is loosened to be movable so that the height of the headrest can be adjusted within a range of the long hole. Further, when the headrest is moved close to or away from the frame to change its height from the headrest retracted position, the restriction pin of one bracket which has been in contact with the shoulder portion of the other bracket moves away from that shoulder portion. Thus, restriction to the relative rotation between the first and second brackets can be canceled to enable tilting. Accordingly, by adjusting the height and the tilt and fastening the coupling means when desired height and tilt are obtained, the headrest can be fixed in a preferable state in accordance with a posture or a symptom of a patient and a head of the patient can be maintained in an appropriate posture.
Moreover, when the restriction pin is brought into contact with the shoulder portion of one bracket, the headrest can be positioned to the headrest retracted position. Therefore, when a patient again transfers from the stretcher to the bed, the headrest can be easily and rapidly returned to its original state flush with or parallel with the headrest retracted position by only lowering the headrest. Consequently, this can not be an obstacle for transfer of a patient.
In addition, it is preferable that at least a pair of friction plates are provided between the first and second brackets. In this case, since a contact area can be enlarged to increase the friction by using the brackets and the friction plates, the headrest can be further assuredly fixed.
Furthermore, it is preferable that at least one of a left side portion or a right side portion of the headrest can be bent toward a head of the patient. In this case, a direction or a position of a patient""s head on the headrest can be maintained in one direction or at a fixed position in the stretcher configuration, and his/her head can be fixed, thereby taking a posture in accordance with a symptom and the like of the patient. Also, in the wheelchair configuration, it is possible to take a comfortable posture by holding his/her head without being tilted.
The headrest according to the present invention divides a region requiring deformation of a core material of a support member supporting a load or at least a support surface of the support member itself and couples the divided core materials or support members with each other by a flexible mechanism, the flexible mechanism comprising: a fixed side member having a plurality of overlapping plates arranged in parallel at intervals; a tilted side member having a plurality of overlapping plates which alternately overlap on the overlapping plates of the fixed side member; a coupling shaft which pierces a overlapping position of each overlapping plate of the fixed side member and the tilted side member to fasten the overlapping plates; and impetus giving means for giving an impetus to the overlapping plates in an overlapping direction. The tilted side member rotates around the coupling shaft to give an angle to a part of the core material and the frictional force at the contact part of both types of the overlapping plates is utilized to maintain that angle so that a shape of the support surface is retained.
In case of this headrest mechanism, the frictional force generated in an overlapping area of the overlapping plates becomes a resistance force for the mutual movement of the divided support members coupled with each other through the overlapping plates and serves as a holding force for maintaining the mechanism for supporting a head at a fixed angle. Therefore, applying an external force above the holding force can incline the support member to a desired angle to deform a shape of the support surface of the headrest. Further, this deformation can be maintained by eliminating the external force at that position unless the external force above the holding force again acts. Since the overlapping plates are constantly fastened by the coupling shaft and also pushed by the impetus giving means, reduction in the frictional force due to slack can be avoided.
Additionally, it is preferable that the impetus giving means takes a form of, e.g., a spring member arranged on the same axis as the coupling shaft. As a result, the impetus giving means can be a flexible mechanism formed integrally with the coupling shaft, and a desired frictional force can be obtained from the overlapping plates. It is to be noted that a helical compression spring or a coned disc spring can be preferably used as the spring member.
Moreover, it is preferable that an impetus of the impetus giving means can be adjustable and the frictional force at the overlapping portion of the overlapping plates is variable. In such a case, by changing the frictional force by adjusting the impetus, a nursing personnel, a caregiver or a patient himself/herself can obtain a flexural strength usable for him/herself in accordance with the state of the patient, e.g., a symptom, a weight or a physical construction. In addition, the headrest can be firmly fixed in an arbitrary shape by fastening using this adjusting means. In this case, if means for adjusting the impetus is exposed to the outside, a user can arbitrarily adjust the impetus according to need to obtain a force required for deformation of the support member with a desired strength.
Here, it is preferable that a part of plural overlapping plates of the headrest is supported by the fixed side member or the tilted side member so as to be capable of slightly moving in the overlapping direction. In such a case, since a gap can be adjusted when alternately inserting and superimposing the overlapping plates of the fixed side member and those of the tilted side member, an overlapping operation during assembling can be facilitated.
It is preferable for the headrest to have such a shape as that its width is narrowed toward a parietal region. In this case, a handle portion can be grabbed while maintaining a body support function of the headrest, and the handle portion can be accommodated in a headrest side portion, thereby minimizing the stretcher when the handle is not used.
The frame of the stretcher according to the present invention comprises: a bracket portion capable of taking up a sheet on which a patient is lying and rotatably supporting a transfer bar for transferring the patient from a bed to the stretcher together with the sheet in a recumbent state; rotating shaft portion having an L shape for supporting the bracket portion; and a displacement fixing means which rotatably couples the shaft portion with the frame on the same axis and fixes them so as not to rotate by fitting at a predetermined rotating position. By rotating the L-shaped shaft portion by using the displacement fixing means so that the bracket portion is switched between a bar support position at which the bracket portion is set upright and a transfer bar can be supported and a retracted position at which the bracket portion is turned down and which does not obstruct a patient to get on and off the stretcher, and the bracket portion can be fixed at each position.
Therefore, when transferring a patient from a bed to the stretcher while keeping the recumbent position, upheaving the bracket portion to be fixed at the bar support position can take up a sheet spread under the patient by attaching the transfer bar to the bracket portion. At this time, the patient can be pulled together with the sheet to be transferred to the stretcher. Further, when moving the patient in the stretcher mode or the wheelchair mode, the bracket portion can be retracted at a position under the mat surface so as not be an obstacle by fixing the bracket portion at a retracted position (this retracted position will be distinguished from the headrest retracted position and referred to as a xe2x80x9cbracket retracted positionxe2x80x9d in this specification), and no annoying feeling can be given. Also, since the bracket portion remains attached to the lever device when the bracket portion is not used, loss of the bracket portion or any damage to the bracket portion after removed can be avoided.
Furthermore, the frame of the stretcher according to the present invention comprises: a lever portion which is gripped by a nursing personnel or a caregiver when pushing the stretcher by hand; and displacement fixing means which rotatably couples the lever portion with the frame on the same axis and fixes them by fitting at a predetermined rotational position so as not to allow rotation. By rotating the lever portion by the displacement fixing means, and changeover is made between a handle position at which the lever portion is upheaved and the nursing personnel or the caregiver can grab the lever portion when pushing the stretcher by hand and a retracted position at which the lever portion is moved down so as not to obstruct a patient to get on and off the stretcher, and the lever portion can be fixed at each position.
In this case, when the lever portion is raised to be fixed at the handle position, the nursing personnel or the caregiver can grab the raised lever portion to push the stretcher. Therefore, since the nursing personnel or the caregiver can push or pull the stretcher in a comfortable posture without his/her body bent forward, which facilitates movement. When the lever portion is fixed at the lever retracted position, since the lever portion becomes lower than the mat surface, it is possible to prevent the lever portion from being an obstacle for a patient to get on and off the stretcher.
Moreover, it is preferable that the lever portion is provided with a bracket portion capable of taking up a sheet on which a patient is lying and rotatably supporting the transfer bar for transferring the patient from a bed to the stretcher together with the sheet in the recumbent state. In this case, since the transfer bar can be supported by the bracket portion, the sheet on which the patient is lying can be taken up to transfer the patient from the bed to the stretcher. In addition, since the bracket portion remains attached to the lever portion even if the bracket portion is not used, which can avoid loss of the bracket portion or any damage to the bracket portion after removal.
Additionally, in the stretcher according to the present invention, second displacement means which rotatably couples the lever portion with the bracket portion on the same axis and fixes them by fitting at a predetermined rotational position so as not to allow rotation is provided between the lever portion and the bracket portion. The bracket portion can be placed at a bar support position at which the transfer bar can be supported by rotating the bracket portion with respect to the lever portion by using the second displacement fixing means when the lever portion is positioned at the handle position, and the bracket portion can be placed at a retracted position by rotating the bracket portion with respect to the lever portion by using the second displacement fixing means when the lever portion is positioned at the retracted position, thereby fixing the bracket portion at each position.
In such a case, the bracket portion can be placed at the bar support position to use the transfer bar by setting upright the lever portion at the handle position and rotating the bracket portion. Further, when accommodating the bracket portion and the lever portion, the bracket portion and the lever portion are rotated to place the lever portion at the lever retracted position. As a result, the bracket portion can be retracted facedown, and hence the lever portion and the bracket portion do not protrude above the mat as well as the side of the same. Therefore, the stretcher can be appressed against the bed and the like to transfer a patient.
Moreover, it is preferable that a grip portion is formed at an end of the lever portion or an end of the bracket portion. In this case, since a nursing personnel or a caregiver can hold the grip portion to push the stretcher, the stretcher can be easily pushed with easy gripping and facilitated application of a force.
Here, the displacement fixing means provided between the frame and the lever portion or the bracket portion or between the lever portion and the bracket portion comprises: impetus giving means which can move a first member and a second member close to or away from each other at the same axis, couples them so as to enable relative rotation and gives an impetus in a direction for moving the first member and the second member close to each other; a plurality of notches formed at an end surface of on one of the first member and the second member; and an engagement protrusion formed to the other of the first member and the second member to be fitted to each notch. Fitting the engagement protrusion in the notch restricts the relative rotation of the first member and the second member and, on the other hand, releasing fitting formed between the notch and the engagement protrusion allows the relative rotation of the first member and the second member.
Therefore, when the engagement protrusion is selectively fitted to the notch, the first member and the second member are coupled with each other so as not to rotate in the circumferential direction. When the first member is pulled away from the second member, engagement is canceled to allow the relative rotation of the first member and the second member. The notch is preferably formed on the inner side of the first member or the second member to prevent clothes or fingers of a user from being caught when the engagement protrusion is fitted to the notch. The present invention is not, however, restricted to this structure, and the notch may reach the peripheral surface of one of the first member and the second member and a cover may be put on the notch from the outside. In such a case, since the cover is put on the notch from the outside, clothes or fingers of a user can be likewise prevented from being accidentally caught between the notch and the engagement protrusion.
In addition, in the stretcher according to the present invention, a bracket is provided on the side part of the armrest portion of the frame; to the bracket is rotatably attached a safety bar which can rotate between a use position at which the safety bar is raised above the mat to prevent a patient from falling off and a retracted position at which the safety bar is retracted below the mat so as not to disturb transfer of a patient; and fixing means for disabling rotation of the safety bar at the use position is provided between the bracket and the safety bar. Consequently, when it is required to prevent a patient from falling off, the safety bar can be set by only rotating it. Furthermore, when the safety bar is unnecessary, it can be retracted below the mat, which can not be an obstacle. Additionally, the safety bar raised above the mat can be fixed so as not to rotate by the fixing means, and the safety bar can not turn the other way round to the retracted position thereof even if an external force is applied. Therefore, a patient can be prevented from falling off. Since the safety bar is integrally provided to the side part of the frame, which can eliminate such a problem as that the safety bar may be lost when removed.
As the fixing means for the safety bar, a pushing pin which is engaged with a concave portion formed to one of the safety bar and the bracket and a concave portion formed to the other and constantly given an impetus is preferred. In this case, engagement between the concave portion and the pushing pin can be released by only pulling the pin, thereby enabling rotation of the safety bar. When the safety bar is rotated and a position of the pushing pin is matched with that of the concave portion, the pushing pin is automatically inserted to be so locked as not to be rotated. At this time, if a shallow recession to which an end of the push-put pin can be slightly inserted is formed on the opposed side of the concave portion, the safety bar at the retracted position does not become staggery, and the pushing pin is automatically moved away from the recession to be rotatable without restraint when trying to rotate the safety bar.
An offset is given to the rotating shaft portion of the safety bar supported by the bracket. With this offset, the safety bar set at the use position is raised up on the outer side so as to project from the side portion of the stretcher, and the safety bar placed at the retracted position is retracted toward the inner side from the side portion of the stretcher. The safety bar in this case is retracted so as to be hidden under the mat so that the stretcher can be appressed against the bed and the like without a gap therebetween. On the other hand, when the safety bar is used, since it is stood up so as to project toward the outer side from the mat, the mat surface can be widely used.
In addition, the safety bar is set in such a manner that either the brackets or the rotating shaft portions of the safety bar fitted in the brackets are opposed to each other and the other members are arranged in the back-to-back direction, and the safety bar is supported in the fixed state disabling movement in the axial direction after fitting the safety bar to the bracket. Therefore, the safety bar is allowed to only rotate and does not move in the axial direction.
It is preferable that the safety bar is assembled in the frame by attaching the bracket to the frame after the bracket is fitted to the rotating shaft portion of the safety bar. According to this method, it is possible to prevent the safety bar from moving in the axial direction after assembling irrespective of a special assembling method or members.